Chen Chih-Ping, Lin Chen-Ju, Chern Schu-Rern, Wu Peih-Shan, Chen Yen-Ni, Chen Shin-Wen, Pan Chen-Wen, Yang Chien-Wen, Wang Wayseen
Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan; Department of Biotechnology, Asia University, Taichung, Taiwan; School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan; Institute of Clinical and Community Health Nursing, National Yang-Ming University, Taipei, Taiwan; Department of Obstetrics and Gynecology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medicine, MacKay Medical College, New Taipei City, Taiwan.
Taiwan J Obstet Gynecol. 2017 Apr;56(2):238-242. doi: 10.1016/j.tjog.2017.01.005.
We present prenatal diagnosis of low-level mosaic trisomy 12.
A 40-year-old woman underwent amniocentesis at 18 weeks of gestation because of advanced maternal age, which revealed a karyotype of 47,XX,+12[5]/46,XX[24] consistent with 17.2% (5/29) mosaicism for trisomy 12. Repeat amniocentesis performed at 21 weeks of gestation revealed a karyotype of 47,XX,+12[4]/46,XX[6] consistent with 40% (4/10) mosaicism for trisomy 12. Interphase fluorescence in situ hybridization (FISH) on 112 uncultured amniocytes detected 23 cells with trisomy 12 consistent with 20.5% (23/112) mosaicism for trisomy 12. Polymorphic DNA marker analysis excluded uniparental disomy 12. Array comparative genomic hybridization (aCGH) on uncultured amniocytes revealed a result of arr 12p13.33q24.33 (230,451-133,773,499) × 2.2, 17p12 (14,191,925-15,442,037) × 1.0 consistent with 10-20% mosaic trisomy 12. The father carried the 17p12 microdeletion. The fetal ultrasound findings were unremarkable. A 3958-g female fetus was delivered at 37 weeks of gestation with no phenotypic abnormality. The cord blood had a karyotype of 46,XX. Postnatal interphase FISH on urinary cells revealed 7.14% (7/98) mosaicism for trisomy 12.
Low-level mosaic trisomy 12 at amniocentesis can be associated with a favorable pregnancy outcome. Interphase FISH and aCGH on uncultured amniocytes are useful for confirmation of low-level mosaic trisomy 12 at amniocentesis.
我们报告12号染色体低水平嵌合三体的产前诊断。
一名40岁女性因母亲年龄较大，在妊娠18周时接受了羊膜腔穿刺术，结果显示核型为47,XX,+12[5]/46,XX[24]，12号染色体三体的嵌合率为17.2%（5/29）。妊娠21周时再次进行羊膜腔穿刺术，核型为47,XX,+12[4]/46,XX[6]，12号染色体三体的嵌合率为40%（4/10）。对112个未培养的羊水细胞进行间期荧光原位杂交（FISH）检测，发现23个细胞存在12号染色体三体，12号染色体三体的嵌合率为20.5%（23/112）。多态性DNA标记分析排除了12号染色体单亲二体。对未培养的羊水细胞进行阵列比较基因组杂交（aCGH），结果为arr 12p13.33q24.33（230,451-133,773,499）×2.2，17p12（14,191,925-15,442,037）×1.0，符合10-20%的12号染色体嵌合三体。父亲携带17p12微缺失。胎儿超声检查结果无异常。妊娠37周时分娩出一名体重3958克的女婴，无表型异常。脐带血核型为46,XX。产后对尿液细胞进行间期FISH检测，发现12号染色体三体的嵌合率为7.14%（7/98）。
羊膜腔穿刺术时发现的12号染色体低水平嵌合三体可能与良好的妊娠结局相关。对未培养的羊水细胞进行间期FISH和aCGH有助于确诊羊膜腔穿刺术时的12号染色体低水平嵌合三体。
